21137787407 has 8 divisors (see below), whose sum is σ = 23225301120. Its totient is φ = 19077923160.

The previous prime is 21137787401. The next prime is 21137787439. The reversal of 21137787407 is 70478773112.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21137787407 - 2⁶ = 21137787343 is a prime.

It is a super-3 number, since 3×21137787407³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21137787401) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6910763 + ... + 6913820.

It is an arithmetic number, because the mean of its divisors is an integer number (2903162640).

Almost surely, 2^21137787407 is an apocalyptic number.

21137787407 is a deficient number, since it is larger than the sum of its proper divisors (2087513713).

21137787407 is a wasteful number, since it uses less digits than its factorization.

21137787407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13824733.

The product of its (nonzero) digits is 460992, while the sum is 47.

The spelling of 21137787407 in words is "twenty-one billion, one hundred thirty-seven million, seven hundred eighty-seven thousand, four hundred seven".